1. Field of the Invention
The present invention relates to endoscopic treatment tools, in particular to treatment tools such as a high-frequency knife for incising biological tissue.
2. Description of the Related Art
Conventionally, a treatment procedure for incising biological tissue such as a mucous membrane has been conducted endoscopically. In such an incision procedure, a high-frequency treatment tool disclosed in such as Japanese Unexamined Utility Model Application, Publication No. S62-50610 is used.
The high-frequency treatment tool such as disclosed in the above document and Japanese Patent Application, First Publication No. Hei 8-299355, and Japanese Patent Application, First Publication No. 2005-230080, include a needle-like electrode (treatment section) which extends to an axial direction disposed at a distal end of an operating wire inserted through a flexible sheath. Biological tissue which is in contact with the electrode knife will be cauterized to incise by transmitting a high-frequency current through the knife.
Tubes and coils may be used for the flexible tube and wires and coils may be used for the operating wire. Thus, flexibility is maintained upon combining the tube and the wire.
However, when incision and excision of tissue is performed with the high-frequency treatment tool disclosed in Japanese Unexamined Utility Model Application, Publication No. S62-50610, a knife 102 of the high-frequency treatment tool 101 disposed at the distal end of an endoscope 100 is pierced to an incision target site A, then incision and excision is performed by moving the knife along the pre-determined incision direction B, such as shown in FIG. 14A.
At this time, backward deflection to the direction of movement of a sheath 103 occurs after the treatment tool is moved due to the flexibility of the sheath 103 of the high-frequency treatment tool 101, hence there have often been problems of insufficient incision and excision relative to the distance of movement of the treatment tool.
Even the treatment tools provided with a tightly wound coil as the flexible tube or the operating wire such as those disclosed in Japanese Patent Application, First Publication No. 8-299355 and Japanese Patent Application, First Publication No. 2005-230080 have the same problems due to the flexibility of the tightly wound coil.
The present invention was conceived in view of the above-described circumstances and has as its objective the provision of an endoscopic treatment tool with which the treatment section is protruded from a flexible pipe-like tube and to prevent deflection of the flexible tube when in use so that a sufficient incision and excision is achieved relative to the distance of the movement of the treatment tool.